US10354219B1

US10354219B1 - Process for selecting an order in an Item-on-Demand order selection system

Info

Publication number: US10354219B1
Application number: US15/782,170
Authority: US
Inventors: Craig Roper; William Schneider
Original assignee: Rosch Logistical Technologies LLC
Current assignee: Rosch Logistical Technologies LLC
Priority date: 2016-10-18
Filing date: 2017-10-12
Publication date: 2019-07-16
Anticipated expiration: 2037-10-12

Abstract

An order selection process is provided for the selecting of a plurality of a predetermined item or items from a stocked picking location in an order selection system. This process includes a method for converting a computer generated order selection form (pick ticket), a method and device for reading the order selection form (pick ticket), and a method for communication with a plurality of discharge conveyors.

Description

REFERENCE TO RELATED APPLICATIONS

This application claims one or more inventions which were disclosed in Provisional Application No. 62/409,584, filed Oct. 18, 2016, entitled “PROCESS FOR SELECTING AN ORDER IN AN ITEM-ON-DEMAND ORDER SELECTION SYSTEM”. The benefit under 35 USC § 119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The invention in general relates to material handling systems in the warehousing and distribution industry and more specifically to the selection of items from a stocked location for conveyance to a packing area for order fulfillment. The invention also relates in general to the field of automatic order selection (goods to person) material handling systems and more specifically to the use of optical recognition scanning as a prime mover in the system.

Description of Related Art

Order selection is the procedure of selecting an item or items typically, but not limited to, less than case lot quantities from a prepared list also known as a “pick ticket” or “order selection form”. These items reside in a main warehouse or distribution center in stocked locations and are selected for transfer to an external wholesale supplier, retail end user, or to a retail outlet for further point of sale distribution.

A number of systems and methods are currently employed by distributors and order selectors to achieve the result of goods or items requested by a purchaser to be selected and brought to a packing area for preparation to ship. This includes order selection from a printed paper order selection form (pick ticket) with human labor performing the physical task of locating, selecting, and movement of the item or items (goods) to a packing area for preparation of shipment. This also includes the use of integrated warehouse management software to select items through the use of electro-mechanical discharging apparatus, automatic sortation systems for routing to destination, and the use of programmed robotic equipment to replace human labor.

In almost all systems and methods, an order selection form (pick ticket) may be printed for use in quality assurance, order selection, and customer shipment information, if required.

Economy of labor and energy consumption to perform the tasks of order selection is an obvious factor of profitability. Increases in speed of order selection are desirable for the distributor/selector to be able to process more goods or items through an existing facility in a shorter amount of time, thereby increasing profitability.

Current and prior art does not sufficiently address the difficulties in an uncomplicated or cost efficient manner.

The most fundamental difficulties are as follows:

- 1. Speed of order selection for availability to the packing area.
- 2. Item-on-demand or goods to person systems that are not conducive to a wide variety or sizes of items to be selected by an order selection process.
- 3. Item-on-demand or goods to person systems that are not energy efficient.
- 4. Item-on-demand or goods to person systems that require an overabundance of physical space to reach an acceptable level of performance.
- 5. Item-on-demand or goods to person systems that are difficult to implement due to major software integrations and the costs associated with these integrations.

SUMMARY OF THE INVENTION

In summary, specifically addressing the difficulties mentioned previously, the invention disclosed in this application is as follows: The use of PLC controlled discharge conveyors utilizing a specifically designed Self Controlled Sheetfeed Optical Recognition Scanner as a prime mover discharges an item or items for conveyance to a packing area at a very high rate of speed resulting in an increase of productivity compared to most conventional methods and current art.

A wide variety of items of different sizes and weights may be processed with this system. Physical detection of an individual item on conveyance is basically the main requirement for usage in this system.

This Item-on-Demand (I.O.D.) system utilizes a start/stop/wait approach to order selection which efficiently keeps the electrical power consumption down to a minimal amount based on the item or items demanded while maintaining a very high rate of order selection speed. The use of modular cubicals containing small parts discharge conveyors and high density arrangements for package, tote, pallet and other conveyors utilizes cubic space availability to a very high degree, utilizing the discharge conveyors as a means of storage.

The rear loading feature of all discharge conveyors, both modular and compacted, reduce the amount of forklift aisles and overall restock/order selection aisles. This also results in a first in/first out discharge of items.

The invention disclosed in this application may be utilized as an adaptive method for warehouse management systems, or order selection software by simply changing the font in the form fields of quantity and location to a barcode font or OCR font and utilizing a specifically designed Self Controlled Sheetfeed Optical Recognition Scanner as a prime mover to initiate the order selection process. This eliminates the need for major software integration changes and/or proprietary software systems for item-on-demand systems. It may operate as a standalone system or may be integrated into other systems for informational purposes.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a flowchart of system components and activity.

FIG. 2 shows a plan view of a self controlled sheetfeed optical scanner.

FIG. 3 shows an overall diagram of an order selection system.

FIG. 4 shows a side view of the main components of a self controlled sheetfeed optical scanner.

FIGS. 5a-5c show examples of a linear read by a self controlled sheetfeed optical scanner.

FIG. 6a shows a side view of a modular cleated discharge belt conveyor, without motor or takeup plate.

FIG. 6b shows a side view of a modular cleated discharge belt conveyor, with motor and takeup plate, but without limit switch or belt.

FIG. 6c shows an aisle side view of a modular cleated discharge belt conveyor.

FIG. 7 shows an end view of a modular cubical of cleated belt discharge conveyors.

FIG. 8 shows a side view of a modular cubical of cleated belt discharge conveyors.

FIGS. 9a-9c show a schematic representation of a trigger method for discharge conveyors.

DETAILED DESCRIPTION OF THE INVENTION

The I.O.D. (Item-on-Demand) system as described herein and shown in diagram form in FIG. 3 is very basically an adaptive process that may be utilized with existing warehouse management systems that produce an order selection form (pick ticket) in printed form.

The system can be used in a warehouse, shown in an example diagram of FIG. 3. It will be understood that the drawing in FIG. 3 is a simplified diagram provided solely to place the invention in context, and is not intended to limit the scope of the invention. The system is usable in many different arrangements and environments, as may be needed by the particular application to which it is applied.

In the example of FIG. 3, a number of storage banks 303 a-303 n are shown, separated by stocking aisles 311. Each bank 303 a-303 n has a plurality of cubical discharge modules 305, each cubical discharge module housing a plurality of cleated discharge belt conveyor modules, which will be shown and described in detail below. The conveyor modules of the discharge modules 305

dispense items

310 onto takeaway conveyors 304 a-304 n. It will be understood that the number and arrangement of takeaway conveyors 304 a-304 n will vary depending on the number and design of the storage banks 303 a-303 n.

The takeaway conveyors 304 a-304 n from each storage bank 303 a-303 n may lead directly to a pickup or packing area 309, or they could deposit items 310 onto one or more connecting belts 308, depending on the particular environment into which the system is installed.

Once the items 310 arrive at the pickup or packing area 308, they can be combined into larger packages or packed for shipping, as is known to the art.

The system begins by modifying the text in the form fields of quantity and location of an order selection form (pick ticket) to a standard 1D barcode font such as code 39 or an OCR character font. This is easily done in most, if not all, current order selection form (pick ticket) software packages.

An order selection form (pick ticket) is then printed in paper form 301 on a printer in a location near to the packaging zone of the order to be selected.

The order selection form (pick ticket) 301 is then introduced into a specifically designed Self Controlled Sheetfeed Optical Recognition Scanner 302 by a human operator. An operator may manage more than one Self Controlled Sheetfeed Optical Recognition Scanner at a time.

The Self Controlled Sheetfeed Optical Recognition Scanner 302 reads the quantity and location of the item or items to be selected by cycling the order selection form (pick ticket) 301 by means of a friction drive roller through an area in which resides a fixed but adjustable optical recognition scanner, as will be described below. The scanner reads the codes or characters and transmits ASCII information to a programmable logic controller (PLC) 307 residing within the Self Controlled Sheetfeed Optical Recognition Scanner 302 assembly.

The PLC 307 then performs two major functions within milliseconds of each other. It first stops the friction drive roller motor of the Self Controlled Sheetfeed Optical Recognition Scanner 302 for the length of time the discharge conveyors are expected to be in discharging mode, and secondly, it sends the appropriate information of quantity and location to a secondary “slave” PLC that resides in a control panel mounted within the discharge conveyor cubical or to a package/tote discharge conveyor control panel in the cubical discharge modules 305 of the storage banks 303 a-303 n.

The stoppage of the friction drive roller motor of the Self Controlled Sheetfeed Optical Recognition Scanner is important to insure that more than one discharge conveyor motor or the Self Controlled Sheetfeed Optical Recognition Scanner drive motor is not operating at the same time. By limiting the operation of multiple motors, this system addresses the concern of energy efficiency.

In an example of efficiency or minimal power consumption, a typical small parts discharge conveyor may use a low voltage (i.e. 12V) DC gear motor drawing less than 3 amps or 36 watts. A typical small parts conveyor may be set to discharge an item or part every 750 milliseconds or ¾ of a second. This would put the average rate of speed of the Self Controlled Sheetfeed Optical Recognition Scanner at 80 items per minute discharged from a discharge conveyor averaging 750 milliseconds per discharge. Multiplied by 60, that puts the operating range of a single Self Controlled Sheetfeed Optical Recognition Scanner at 60×80=4,800 items per hour. This is done with not more than one motor drawing less than 3 amps at 12 volts DC (36 watts) at a time.

The above example is a typical small parts discharge conveyor. Other discharge conveyors may be larger and require longer run times (reducing selective time rates) and more amperage consumption, but the concept is clearly the same. An example of a larger discharge conveyor would be a standard line shaft roller conveyor operating at 65 feet per minute (or 923 milliseconds per foot). Using a package or tote size of 2 feet in length the discharge time would be 1.846 seconds per item. 60 seconds divided by 1.846=32.5 items discharged per minute or 1,950 packages or totes per hour. In a typical warehouse or distribution application (e-commerce for example) a 2 foot long package is reaching the high end of typically shipped items. For larger items such as the package or tote application a 3 phase motor in the range of 460 volts could be used for the application. On a standard ¾ horsepower 460V 3 phase motor the current draw would be near the 1.4 amp range (or 644 watts).

The above examples are randomly picked sizes and possibilities of the system to address the issue of energy efficiency and may not apply in all scenarios. The type of discharge system will be product oriented and customer driven, designed specifically for each application based on speed of discharge requirements, available electrical power supply, and product weight.

If the items 310 requested are small parts, they may be discharged onto a conventional troughed slider bed belt conveyor 308 for conveyance to the appropriate packaging zone 309 or discharged to a chute or tilted tray or pan arrangement to be prepared for shipment or cycled to the next appropriate zone for combination with an item or items selected and delivered to that zone in the case of multiple zone orders.

If the items requested are boxed (package) or totes, or pallets, then standard conveyor appropriate for the item may be utilized to convey to a packaging or shipping area where applicable. Standard sortation methods including, but not limited to, barcode sortation may be utilized.

The Self Controlled Sheetfeed Optical Recognition Scanner 302 then restarts the drive motor and the cycle begins again until all parameter sets on the existing page are read, and all other pages in the Self Controlled Sheetfeed Optical Recognition Scanner assembly have been processed.

Operation of System Components

FIG. 1 shows a flowchart of the operation of the system of the invention.

Step 101: The form fields of item quantity and location on the order selection form (pick ticket) must be modified to an optically recognized font for use in the specifically designed Self Controlled Sheetfeed Optical Recognition Scanner. These fonts may be a 1D linear barcode font or an OCR readable character font. This is done primarily in the settings of fonts in the applicable program used to generate the order selection form (pick ticket).
Step 102: An order for selection is placed with the distributor/wholesaler, etc. who utilizes the Item-on-demand (I.O.D) system.
Step 103: An order selection form (pick ticket) is printed in a location of close proximity to the packing area where the discharged items are expected to arrive. The specifically designed Self Controlled Sheetfeed Optical Recognition Scanner is also located in close proximity to the pick ticket printer. This enables the pick ticket to be conveniently added to the physical item or items as they are prepared for packaging.
Step 104: The specifically designed Self Controlled Sheetfeed Optical Recognition Scanner operator feeds the pick ticket/s into the specifically designed Self Controlled Sheetfeed Optical Recognition Scanner face up in preparation for beginning the cycle of order selection/discharge.
Step 105: The Initiate (Start) button is pressed and the friction drive roller motor engages momentarily.
Step 106: The friction drive roller makes contact with the order selection form (pick ticket) and drives the form from the holding area in the infeed section to the read area in the discharge section. A paper photoelectric proximity sensor reads that there is a form present and continues supplying power to the friction drive roller motor via a relay in conjunction with the master PLC ladder logic.
Step 107: The optical recognition scanner in the read area then reads the first set of quantity and location as two separate instructions.
Step 108: The scanner then sends the information as ASCII information to the specifically designed Self Controlled Sheetfeed Optical Recognition Scanner Master PLC through a com port on the master PLC located in the specifically designed Self Controlled Sheetfeed Optical Recognition Scanner assembly.
Step 109: The master PLC receives the information from the scanner and reacts to the information by executing commands based on the ASCII information it has received.
Step 110: The master PLC program executes its ladder logic program based on the “equal to” or “not equal to” information received from the scanner.
Step 110 a: One of the initial main functions of the master PLC ladder logic program is to disengage or “stop” the friction drive roller motor electrically for the expected duration of the item or items to be discharged (selected) from the discharge conveyors. This insures that the scanner will not read another set of parameters from the order selection form and engage another discharge conveyor. This is done to conserve available electrical power supplies and usage.
Step 110 b: Another initial main function of the master PLC ladder logic program is to send information via hardwire or wireless communication through a com port to the slave PLC which resides in a discharge conveyor control panel. The information sent is specific to the location relays programmed into the slave PLC ladder logic program. There may be many multiples of discharge conveyor control panels with slave PLC's residing in the control panels.
Step 111: The slave PLC ladder logic program reacts to the information received from the master PLC.
Step 112: The slave PLC ladder logic program contains the information for the control relay triggers of the discharge conveyors.
Step 112 a: The slave PLC executes a trigger signal to the appropriate discharge conveyor for a specified length of time based on the quantity of an item or items to be discharged. The speed of the discharge conveyors and the length (travel distance) of items to be discharged are known entities and easily programmed to suit application. Differences in electric motor performances are easily compensated for in this programming.
Step 113: The slave PLC completes it's cycle and awaits instruction from the master PLC.
Step 113 a: At this point, the item or items are already discharged from the discharge conveyor and available for conveyance to the packing area.
Step 114: The discharge conveyor is stopped by means of an integral signal switch either mechanical/electrical in the case of cleated belt discharge conveyors or photoelectric/proximity sensors in the case of package, tote, pallet or chain conveyor discharge conveyors.
Step 115: At this point, the expected duration of discharge has elapsed and the timers programmed into the ladder logic of the master PLC allow the friction drive roller motor to begin the cycle again, driving the next set of parameters on the order selection form into the scan/read area in the specifically designed Self Controlled Sheetfeed Optical Recognition Scanner.
Step 115 a: The master PLC reads the next set of parameters and repeats the cycle as per starting point of “107” in this flow chart.
Step 116: The item or items discharged from the discharge conveyors are conveyed by means of standard conveyance appropriate to the discharge conveyors and products stored on the discharge conveyors. In the case of small parts, items may be conveyed to or directly delivered to a tilted pan, tray, or chute system designed for the specific application in the appropriate packing area. In the case of package, tote, or pallet conveyor, standard methods of stops, traffic cops metering belts, and sortation may be used for conveyance to the appropriate packing area. In the case of chain conveyor, appropriate transfers, pick ups and releases may be utilized for conveyance to the appropriate packing area. All methods of conveyance to the appropriate packing area are subject to the properties of the item or items to be conveyed and existing standard methods have been proven reliable and efficient in the material handling industry.
Step 116 a. After standard conveyance from the discharge conveyors the item or items arrive in the predetermined packing area.
Step 116 b: If the order is completed in this area (no further selections), the order is packed and sent to the shipping area via convenient means based on throughput, size, and other shipping considerations. This may mean standard conveyance, the use of multiple loaded totes, and/or palletization.
Step 116 c: If the order is not complete, then the product is cycled to the next appropriate zone/s for completion of order. Again, the nature and properties of the product determine the method of conveyance to the next appropriate zone.

Self-Controlled Sheetfeed Optical Scanner

FIG. 2 shows a plan view of a Self-Controlled Sheetfeed Optical Scanner of the system of the invention, and FIG. 4 shows a side view of the main components of the Self-Controlled Sheetfeed Optical Scanner of the invention.

Item

201 is a motor, preferably a low voltage, low amperage DC geared motor capable of at least 40 RPM, continuous duty, and able to drive the friction roller 218 suitable for cycling a sheet from the infeed section 203 into the read area 216 of the scanner. The paper infeed area 203 is supplied with adjustment holes for paper alignment.

An adjustable paper width guide 202 is provided in the infeed section 203 for alignment purposes of the order selection form as it enters the input side 220 of the infeed section 203. The infeed section 203 and guide 202 may be metal, plastic, or chemical composite in construction. A hinged location and portion 204 of the paper infeed area 203 is tensioned to provide introduction of the order selection form to the friction drive roller 218, which is an adjustable roller of metal, plastic, or chemical composite material with an attached sleeve of friction enhancing material such as latex, rubber, urethane, or other suitable chemical composite material. The roller 218 engages an order selection form and drives it through to the scanner read area 216. An infeed stop 408 can be provided to hold order selection form(s) in the infeed area 203 until they engage roller 218 and are moved on into the read area 216.

Relay

205 controls the power feed to the friction drive roller motor 201. Spring tensioned lever arm 213 is used for releasing an order selection form from friction drive roller 218 and engaging tension between the order selection form and drive roller 218.

When the drive roller 218 moves a form into the read area 216, it is read by Optical recognition scanner 215. The scanner 215 is of a type capable of reading the optical recognition indicia on the order form of the types which were chosen to be used in the system, as will be explained below.

Primary photoelectric/proximity sensor 217 senses sheet activity in the read area 216 to allow friction drive motor 218 to run if a page is in the reading area 216. Secondary photoelectric/proximity sensor 214 senses a page at the discharge end 221 of the read area 216, which gives additional control for multiple sheet feeds.

An Initiate (start) button 219 is provided to momentarily cycle the motor 201 to introduce the order selection form into the read area 216 where the primary photoelectric/proximity sensor 217 picks up the contact and supplies power to the friction drive roller motor 201, possibly via a low voltage relay.

Power supply for the scanner is provided by the main power feed 206, which is typically at 110 VAC, through fuse 208. This supplies a power supply 209 for low voltage circuit which provides power for friction drive roller motor 201 and photoelectric/

proximity sensors

214 and 217. The power supply 209 is preferably protected by a fuse 208. The other components of the scanner can be powered by power supply 209, or, as shown in the figure, by separate power supplies 210 for the Master Programmable Logic Controller (PLC) 212 and 211 for the scanner circuitry.

FIGS. 5a-5c show three examples of a linear scan read on a typical order selection form or pick ticket 501, as the form 501 passes through the scanner in the direction noted by arrow 510.

The blocks 502 on form 501 which are marked with “X” are optical recognition form fields, and these may be of any sort known to the art, for example bar codes (linear or two-dimensional), target codes, or optical character recognition (OCR) areas for printed or handwritten indicia. The line 503 marked “SR” shows the lineal scan read area. The angle and height of read is adjustable on the scanner in the specifically designed Self Controlled Sheetfeed Optical Recognition Scanner assembly. Variations of font size, length of item location, and form field dimensions will determine the placement of the scan area reader.

Cleated Discharge Belt Conveyor Module

FIGS. 6a-6c show various views of a Cleated Discharge Belt Conveyor Module 600 of the system of the invention. FIGS. 6a and 6b show the same view with the motor 608 and takeup plate 609 removed in FIG. 6a , and the limit switch 605 and belt 604 not shown in FIG. 6b . FIG. 6c shows an aisle side view of the side plate 601, motor 608 and discharge conveyor module plug 606.

A flexible belt 604 moves items or products from a load end of the module 600 to a discharge end. The belt 604 is preferably, as shown the figures, a cleated belt having cleats 610 spaced along its length, is usually made of limited stretch material such as polypropylene or canvas weave with synthetic or natural laminations. It is designed to provide equal lengths between cleats 610 for product orientation. It is typically spliced together using a metal hook and pin arrangement but may also be spliced using chemical bonding or heat bonding materials.

A limit switch 605 provides an indication of the position of the belt 604 by detecting the presence of the cleats 610 or items on the belt. The limit switch 605 could be implemented as a physical switch as shown in FIG. 6a which contacts the cleats 610, or a photoelectric sensor detecting an interruption of a light beam by an item or cleat 610, or a magnetic reed switch or Hall-effect sensor operated by magnets on the cleats 610, or an ultrasonic proximity detector, or other sensors known to the art. An explanation of operation of the limit switch 605 in the operation of the system is provided below with respect to the operating states shown in FIGS. 9a -9 c.

Two side plates 601 form the vertical structural members of the cleated belt conveyor module 600. These may be of varying lengths and heights appropriately designed for specific product requirements. The horizontal structural member 603 referred to as a “slider bed” extends between the side plates 601. This structural member 603 supports the belt 604 as it is pulled to the discharge end of the conveyor 600. It also supports the weight of the product on the belt 604, reducing the amount of energy to move the product to the amount of sliding frictional force to overcome. Side plates 601 and structural member 603 may be manufactured from steel, alloy materials, plastic, or chemical composite materials.

Motor

608 is preferably a low voltage, low amperage DC motor sized as per application requirements. The motor 608 is fixed to the side plates 601. Main drive roller 602 is fixed to the drive motor 608 shaft and is utilized to create the pulling force on the belt 604. Take up pulley 607, mounted on take up plates 609, is adjustable to take the slack out of the belt. The main drive roller 602, take up pulley 607 and take up plate 609 can be manufactured from steel, alloy materials, plastic, or chemical composite materials.

Modular discharge conveyor module connector 606 connects the trigger feed, ground, and constant voltage feed of the discharge conveyor module 600 to a matching connector 809 on the cubical discharge module 702, as shown and discussed below in connection with FIGS. 7 and 8.

FIG. 7 shows the high density capabilities of the discharge conveyor modules 600 used in a cubical discharge module 702, shown from an end. FIG. 8 shows a side detail view of a portion of two cubical discharge modules 702 with six discharge conveyor modules 600. The structural support 703 for the cubical discharge module 702 is typically steel, such as pallet racking or a specifically engineered structure to suit application purposes.

The cubical discharge modules 702 may be designed using steel, alloy materials, plastic, or chemical composite materials as per the application requirement. Each cubical discharge module 702 will have a control panel 802 which houses the slave PLC and control relays for the discharge conveyor modules 600 in the cubical discharge module 702. In a very simple manner, an individual discharge conveyor module 600 can have its connector 606 disengaged from the matching connector 809 on the cubical discharge module 702 and removed for restocking of product between the cleats 610, then replaced.

A plurality of discharge conveyor modules 600 as described above are mounted in a support structure 805 in the form of a modular cubical framework which supports the discharge conveyor modules 600 and resides in the structural framework of a pallet rack or design engineered steelwork 803. Size and characteristics of the framewark are designed as per application.

Each cubical discharge module 702 will have a control panel 802 which houses the slave PLC and control relays for the discharge conveyor modules 600 in the cubical discharge module 702.

A takeaway conveyance 804, shown in FIG. 8 as a typical trough conveyor, moves items or products dispensed to a packing area. Application will determine size, quantity and type of conveyance 804.

Trigger Method for Operation of Discharge Conveyors

FIGS. 9a-9c show the three basic states of the discharge conveyor module 600 switch circuit. In each figure, power is supplied through a power input 901 through a limit switch 605. The output 902 of limit switch 605 is coupled to the motor or relay lead 905 which powers belt motor 608 and relay 903. It will be understood that the motor or relay lead 905 may power a motor 608 and relay 903 in parallel as shown in the figure, or it may power only one of the discharge motor 608 or relay 903 which can then power a larger type of discharge conveyor such as package, pallet, chain, etc. . . . . In another embodiment the power from the motor or relay lead 905 may be arranged to power the motor 608 and relay 903 sequentially to reduce available power requirements.

The limit switch 605 is operated by the belt cleats 610 on the belt 604 or, alternatively, by the presence of an item on the belt 604, arranged so that the switch 605 is open (does not supply power to the motor or relay lead 905 through switch output 902) when a cleat 610 or item is present in proximity to the switch 605, and the switch 605 is closed (supplies power to the motor or relay lead 905 through the switch output 902) when the switch 605 is in between cleats 610 or items.

A PLC trigger line 906 leading from the slave PLC in parallel with the limit switch 605 circuit, allows the PLC to close a switch 907 and power the motor 608 or relay 903, independent of the position of the limit switch 605.

The three basic states are as follows:

READY STATE: As shown in FIG. 9a , in this state the conveyor module 600 is inactive. The proximity of a cleat 610 or item holds the limit switch 605 in the open position, so that switch output 902 is unpowered. The PLC trigger line 906 is also unpowered, so that PLC trigger switch 907 is also open. With both switches 605 and 907 open, there is no power on the motor or relay lead 905 and motor 608 and relay 903 are unpowered, so that the belt 604 is stationary.
TRIGGER STATE: As shown in FIG. 9b , in the trigger state the PLC puts a trigger signal on the PLC trigger line 906, so that PLC trigger switch 907 closes. This supplies power to the motor or relay lead 905, which powers motor 608 and relay 903. The motor 608 causes belt 604 to move. The trigger signal needs to remain on the PLC trigger line 906 only long enough to move the belt 604 enough to move the cleat 610 or item away from the limit switch 605, so that limit switch 605 changes to the closed position, supplying power to switch output 902. This puts the system in operation state, see FIG. 9c , below.
OPERATION STATE: As shown in FIG. 9c , once the cleat 610 has moved away from the limit switch 605, the switch 605 is in the closed position, supplying power through the switch output 902 to the motor or relay lead 905, which keeps the motor 608 powered, even though trigger switch 907 has opened. The belt 604 continues to move until a cleat 610 or item arrives in proximity to the limit switch 605, which causes the switch 605 to open, and the system returns to the ready state, FIG. 9a , above.

As explained above, this allows the PLC to dispense a single item on the belt by momentarily triggering switch 907 just long enough for the system to enter operational state. The belt 604 moves just far enough to move the next cleat 610 or item to the limit switch 605, then stops. If it is desired to dispense more than one item, the PLC can simply repeat the process multiple times, triggering the system from ready state to trigger state to operational state and back to ready state as many times as needed.

Alternatively, more than one item can be dispensed in a continuous manner without starting and stopping the belt by prolonging the trigger state of FIG. 9b . The item quantity would be determined by the length of time the signal on the PLC trigger line 906 holds trigger switch 907 closed.

This can be accomplished by calculation, if the belt speed and the length of the product or distance between cleats are known values. In such an embodiment, the PLC would determine how long the belt would have to move until the belt length has passed the limit switch 605, then hold the trigger switch 907 closed for that length of time. The trigger switch 907 would then be opened, and the belt would continue to move in operational state until the next cleat or item causes the system to go back into ready state, as described above. The calculation of the required length of time the trigger signal needs to be held for a given quantity can be done as part of the determining process done by the PLC. Alternatively, a predetermined length of time can be pre-calculated and programmed into the PLC for each of the known quantities and locations of the individual discharge conveyor modules, so that the determining process is performed by using the quantity to look up the predetermined time.

For example, suppose it takes 750 milliseconds for the belt to move sufficiently to discharge a single item (or for the cleat arrangement to move one cleat), and suppose it takes at least 150 milliseconds for the belt to move enough to allow the system to switch from trigger state to operational state (that is, to move the belt enough so that the limit switch 605 takes over powering the motor 608 from the trigger switch 907). To dispense one item, the trigger signal would need to be at least 150 milliseconds duration—after that, the normal operation of the system will return to ready state after the single item is dispensed. To dispense two items, the trigger signal would need to be 150 milliseconds to start the belt, plus 600 milliseconds for remaining movement of the first item (at this time the system would normally return to ready state because a cleat or item opens the limit switch, but because the trigger signal is still closing the trigger switch the belt keeps on moving), plus 150 milliseconds more to keep the belt moving long enough to close the limit switch and start the operational state again to dispense the second package, for a total of 900 millisecond trigger signal duration. Further quantities utilize the same calculations for the trigger signal.

Alternatively, the PLC could have an input monitoring the state of the limit switch 605, so that if it were desired to dispense more than one item the PLC would raise a trigger signal to close the trigger switch 907 and cause the system to enter operational state, and then hold the trigger signal until the limit switch 605 has closed one fewer time than the number of items to be dispensed. Then the trigger signal can be lifted, and the system will remain in operational state long enough to dispense one more item, then re-enter ready state as normal.

Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.

Claims

What is claimed is:

1. An item-on-demand dispensing system, comprising:

a plurality of storage banks for storing and dispensing items, each storage bank comprising:

a plurality of cubical discharge modules, each cubical discharge module comprising:

a plurality of discharge conveyor modules for dispensing items, each discharge conveyor module having a roller conveyor or flexible belt conveyor for storing and moving a plurality of items between a load end and a discharge end of the conveyor, and a motor for driving the conveyor;

a plurality of takeaway conveyors located along a length of at least one of the storage banks, adjacent to the discharge end of the plurality of discharge conveyors, each of the plurality of takeaway conveyors having a length and a discharge end, such that items discharged from the discharge end of the discharge conveyors are deposited onto the length of the takeaway conveyors;

a packing area for receiving items from the plurality of takeaway conveyors;

at least one optical scanner for scanning order selection forms specifying items to be dispensed; and

a controller coupled to the plurality of storage banks, the plurality of takeaway conveyors, and the optical scanner;

the controller being programmed such that when an order selection form specifying an item to be dispensed is scanned by the at least one optical scanner, a discharge conveyor module containing the item is operated to dispense the item from the discharge end of the discharge conveyor module onto a takeaway conveyor, the takeaway conveyor conveys the item to the discharge end of the takeaway conveyor, and the item specified on the order is dispensed into the packing area.

2. The system of claim 1, in which the flexible belt conveyor of the discharge conveyors are cleated.

3. The system of claim 1, further comprising a printer in a location near to the packing area for printing order selection forms for reading by the optical scanner.

4. The system of claim 1, in which each of the plurality of storage banks further comprises at least one slave controller coupled to the discharge conveyor modules in the cubical discharge module, and the controller is coupled to the storage banks through the at least one slave controller of the storage bank.

5. The system of claim 4, in which the at least one slave controller comprises a slave controller in each of the cubical discharge modules of the storage bank.

6. A self-controlled sheetfeed optical scanner reading an order selection form with order information in an item-on-demand dispensing system, comprising:

an infeed section for holding a stack of order selection forms, comprising:

an input section;

a guide for centering paper on the input section;

a hinged portion on a lower end of the input section;

an infeed stop for holding the stack of order selection forms in the infeed section;

a drive roller adjacent to the hinged portion of the infeed section, the hinged portion of the infeed section being tensioned to bring an uppermost order selection form from a stack held on the infeed section into contact with the drive roller;

a read area adjacent to the driver roller, comprising:

a primary proximity sensor adjacent to the drive roller for sensing the presence of an order selection form entering the read area; and

an optical scanner located above the read area, optically scanning a linear area across a width of the read area, imaging optical recognition indicia on the order selection form as the order selection form passes through the read area;

a motor coupled to the drive roller, for rotation of the drive roller such that actuation of the motor rotates the drive roller, moving the uppermost order selection form from the infeed section into the read area; and

a controller coupled to the optical scanner, the primary proximity sensor and the motor, having an input for receiving an instruction to initiate a read operation and an output for transmitting scanned order information derived from the optical recognition indicia on the order form in the read area to a system controller of the item-on-demand dispensing system;

the controller being programmed such that:

when the controller receives an instruction to initiate a read operation, the controller activates the drive roller to feed the uppermost order selection form from the hinged portion of the input section into the read area;

the presence of the order selection form is sensed by the primary proximity sensor;

the optical scanner is activated to scan the linear area across the width of the read area, imaging optical recognition indicia on the order selection form as the order selection form passes through the read area and sending imaging data to the controller;

the controller accepts the imaging data from the optical scanner, processing the imaging data to derive a quantity and a location for each item on the order selection form in the read area which is to be dispensed by the item-on-demand dispensing system;

when all of optical recognition indicia on the order selection form in the read area have been imaged and the imaging data has been processed by the controller, the controller sends the quantity and location for each item on the order selection form in the read area which is to be dispensed by the item-on-demand dispensing system through the output to the system controller of the item-on-demand dispensing system;

wherein the drive motor of the sheetfeed optical scanner is not activated while the item-on-demand dispensing system is dispensing items from the order selection form and when the primary proximity sensor senses that an end of the order selection form has passed into the read area, the controller stops a drive motor of the sheetfeed optical scanner.

7. The sheetfeed optical scanner of claim 6, further comprising a secondary proximity sensor adjacent to an exit end of the read area, coupled to the controller, for sensing the presence of an order selection form discharging from the read area.

8. The sheetfeed optical scanner of claim 6, in which the optical recognition indicia are selected from a group consisting of: machine-readable codes and optical character recognized text.

9. The sheetfeed optical scanner of claim 6, in which the controller further comprises an input for suspending read operation while the item-on-demand dispensing system is dispensing an order, and the controller is further programmed such that the drive motor is only activated when there is no indication on the input for suspending read operation.

10. The sheetfeed optical scanner of claim 6, in which the controller is further programmed to start a timer upon stopping the drive motor, and does not activate the drive motor again until the timer has indicated the passage of a time sufficient for the item-on-demand dispensing system to dispense the items on the order selection form.

11. The sheetfeed optical scanner of claim 6, in which the guide of the input section is adjustable to accommodate order selection forms of differing widths.

12. The sheetfeed optical scanner of claim 6, further comprising a spring tensioned lever arm coupled to the hinged area of the infeed section, for releasing and engaging tension between the uppermost order selection form and the drive roller.

13. The sheetfeed optical scanner of claim 6, further comprising an initiate button coupled to the input for receiving an instruction to initiate a read operation of the controller, such that operating the initiation button sends an instruction to initiate a read operation to the controller.

14. A method of operating an item-on-demand dispensing system comprising a plurality of storage banks for storing and dispensing items, each storage bank comprising a plurality of cubical discharge modules, each cubical discharge module comprising a plurality of discharge roller conveyors or discharge belt conveyors for dispensing items, each discharge conveyor having rollers or a flexible belt for storing and moving a plurality of items between a load end and a discharge end of the rollers or flexible belt, and a motor for driving the rollers or the flexible belt; a plurality of takeaway conveyors located along a length of at least one of the storage banks, adjacent to the discharge end of the plurality of discharge conveyors, each of the plurality of takeaway conveyors having a length and a discharge end, such that items discharged from the discharge end of the discharge conveyors are deposited onto the length of the takeaway conveyors; a packing area for receiving items from the plurality of takeaway conveyors; at least one optical scanner for scanning order selection forms specifying items to be dispensed; and a controller coupled to the plurality of storage banks, the plurality of takeaway conveyors, and the optical scanner; the method comprising the steps of:

a) receiving an order specifying at least one item for dispensing by the item-on-demand dispensing system;

b) printing an order selection form bearing optical recognition indicia specifying a quantity and a location for at least one item on the order which is to be dispensed by the item-on-demand dispensing system;

c) optically scanning the order selection form by the at least one optical scanner;

d) the optical scanner sending the quantity and location for the at least one item on the order selection form which is to be dispensed by the item-on-demand dispensing system to the system controller of the item-on-demand dispensing system;

e) the system controller operating a discharge conveyor module containing the at least one item to dispense the at least one item from the discharge end of the discharge conveyor module onto a takeaway conveyor;

f) the takeaway conveyor conveying the at least one item to the discharge end of the takeaway conveyor, and dispensing the at least one item into the packing area;

g) if there are more items on the order to be dispensed by the item-on-demand dispensing system, the system controller repeating steps (e) and (f) until all items on the order have been dispensed.

15. The method of claim 14, in which step (c) of optically scanning the order selection form is performed by a self-controlled sheetfeed optical scanner comprising an infeed section for holding a stack of order selection forms, comprising an input section; a guide for centering paper on the input section; a hinged portion on a lower end of the input section; an infeed stop for holding the stack of order selection forms in the infeed section; a drive roller adjacent to the hinged portion of the infeed section, the hinged portion of the infeed section being tensioned to bring an uppermost order selection form from a stack held on the infeed section into contact with the drive roller; a read area adjacent to the driver roller, comprising a primary proximity sensor adjacent to the drive roller for sensing the presence of an order selection form entering the read area; and an optical scanner located above the read area, optically scanning a linear area across a width of the read area, imaging optical recognition indicia on the order selection form as the order selection form passes through the read area; a motor coupled to the drive roller, for rotation of the drive roller such that actuation of the motor rotates the drive roller, moving the uppermost order selection form from the infeed section into the read area; and a controller coupled to the optical scanner, the primary proximity sensor and the motor, having an input for receiving an instruction to initiate a read operation and an output for transmitting scanned order information derived from the optical recognition indicia on the order form in the read area to a system controller of the item-on-demand dispensing system; and the method of step (c) comprises the steps of:

the controller receiving an instruction to initiate a read operation;

the controller activating the drive roller to feed the uppermost order selection form from the hinged portion of the input section into the read area;

the primary proximity sensor sensing the presence of the order selection form;

activating the optical scanner to scan the linear area across the width of the read area;

the optical scanner imaging optical recognition indicia on the order selection form as the order selection form passes through the read area and sending imaging data to the controller;

the controller accepting the imaging data from the optical scanner;

the controller processing the imaging data to derive a quantity and a location for each item on the order selection form in the read area;

when all of optical recognition indicia on the order selection form in the read area have been imaged and the imaging data has been processed by the controller, the controller sending the quantity and location for each item on the order selection form in the read area which is to be dispensed by the item-on-demand dispensing system through the output to the system controller of the item-on-demand dispensing system.

16. The method of claim 15, in which the controller of the self-controlled sheetfeed optical scanner further comprises an input for suspending read operation while the item-on-demand dispensing system is dispensing an order, and method further comprises the step of the system controller sending an indication to the input for suspending read operations during the execution of steps (e) through (g), such that the drive motor of the self-controlled sheetfeed optical scanner will not be activated while the item-on-demand dispensing system is dispensing items from an order selection sheet.

17. The method of claim 14, in which the item-on-demand dispensing system further comprises at least one connecting roller or belt conveyor having a length located adjacent to the discharge ends of the plurality of takeaway conveyors, a discharge end adjacent to the packing area, and a motor for driving the connecting roller or belt conveyor, and the method further comprises the system controller operating the motor of the connecting roller or belt conveyor such that items discharged from the discharge end of the plurality of takeaway conveyors are deposited onto the length of the connecting roller or belt conveyor and conveyed to the packing area.

18. The method of claim 14, in which each of the plurality of storage banks further comprises at least one slave controller coupled to the discharge conveyor modules in the cubical discharge module, and the controller is coupled to the storage banks through the at least one slave controller of the storage bank, and step (e) of the system controller operating the discharge conveyor module is performed by the system controller sending commands to the at least one slave controller.

19. The method of claim 18, in which the at least one slave controller comprises a slave controller in each of the cubical discharge modules of the storage bank.

20. The method of claim 14, in which the optical recognition indicia is selected from a group consisting of: machine-readable codes and optical character recognized text.